/*
 * Copyright (c) 2007, 2015, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */
/*
 * Copyright 2001-2004 The Apache Software Foundation.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
/*
 * $Id: IntegerArray.java,v 1.2.4.1 2005/09/06 11:44:56 pvedula Exp $
 */

package com.sun.org.apache.xalan.internal.xsltc.util;

/**
 * @author Jacek Ambroziak
 */
public final class IntegerArray {

  private static final int InitialSize = 32;

  private int[] _array;
  private int _size;
  private int _free = 0;

  public IntegerArray() {
    this(InitialSize);
  }

  public IntegerArray(int size) {
    _array = new int[_size = size];
  }

  public IntegerArray(int[] array) {
    this(array.length);
    System.arraycopy(array, 0, _array, 0, _free = _size);
  }

  public void clear() {
    _free = 0;
  }

  public Object clone() {
    final IntegerArray clone = new IntegerArray(_free > 0 ? _free : 1);
    System.arraycopy(_array, 0, clone._array, 0, _free);
    clone._free = _free;
    return clone;
  }

  public int[] toIntArray() {
    final int[] result = new int[cardinality()];
    System.arraycopy(_array, 0, result, 0, cardinality());
    return result;
  }

  public final int at(int index) {
    return _array[index];
  }

  public final void set(int index, int value) {
    _array[index] = value;
  }

  public int indexOf(int n) {
    for (int i = 0; i < _free; i++) {
      if (n == _array[i]) {
        return i;
      }
    }
    return -1;
  }

  public final void add(int value) {
    if (_free == _size) {
      growArray(_size * 2);
    }
    _array[_free++] = value;
  }

  /**
   * Adds new int at the end if not already present.
   */
  public void addNew(int value) {
    for (int i = 0; i < _free; i++) {
      if (_array[i] == value) {
        return;  // already in array
      }
    }
    add(value);
  }

  public void reverse() {
    int left = 0;
    int right = _free - 1;

    while (left < right) {
      int temp = _array[left];
      _array[left++] = _array[right];
      _array[right--] = temp;
    }
  }

  /**
   * Merge two sorted arrays and eliminate duplicates.
   * Elements of the other IntegerArray must not be changed.
   */
  public void merge(final IntegerArray other) {
    final int newSize = _free + other._free;
// System.out.println("IntegerArray.merge() begin newSize = " + newSize);
    int[] newArray = new int[newSize];

    // Merge the two arrays
    int i = 0, j = 0, k;
    for (k = 0; i < _free && j < other._free; k++) {
      int x = _array[i];
      int y = other._array[j];

      if (x < y) {
        newArray[k] = x;
        i++;
      } else if (x > y) {
        newArray[k] = y;
        j++;
      } else {
        newArray[k] = x;
        i++;
        j++;
      }
    }

    // Copy the rest if of different lengths
    if (i >= _free) {
      while (j < other._free) {
        newArray[k++] = other._array[j++];
      }
    } else {
      while (i < _free) {
        newArray[k++] = _array[i++];
      }
    }

    // Update reference to this array
    _array = newArray;
    _free = _size = newSize;
// System.out.println("IntegerArray.merge() end");
  }

  public void sort() {
    quicksort(_array, 0, _free - 1);
  }

  private static void quicksort(int[] array, int p, int r) {
    if (p < r) {
      final int q = partition(array, p, r);
      quicksort(array, p, q);
      quicksort(array, q + 1, r);
    }
  }

  private static int partition(int[] array, int p, int r) {
    final int x = array[(p + r) >>> 1];
    int i = p - 1;
    int j = r + 1;

    while (true) {
      while (x < array[--j]) {
        ;
      }
      while (x > array[++i]) {
        ;
      }
      if (i < j) {
        int temp = array[i];
        array[i] = array[j];
        array[j] = temp;
      } else {
        return j;
      }
    }
  }

  private void growArray(int size) {
    final int[] newArray = new int[_size = size];
    System.arraycopy(_array, 0, newArray, 0, _free);
    _array = newArray;
  }

  public int popLast() {
    return _array[--_free];
  }

  public int last() {
    return _array[_free - 1];
  }

  public void setLast(int n) {
    _array[_free - 1] = n;
  }

  public void pop() {
    _free--;
  }

  public void pop(int n) {
    _free -= n;
  }

  public final int cardinality() {
    return _free;
  }

  public void print(java.io.PrintStream out) {
    if (_free > 0) {
      for (int i = 0; i < _free - 1; i++) {
        out.print(_array[i]);
        out.print(' ');
      }
      out.println(_array[_free - 1]);
    } else {
      out.println("IntegerArray: empty");
    }
  }
}
